Impact of mycoheterotrophy on the growth of Gentiana zollingeri (Gentianaceae), as suggested by size variation, morphology, and 13C abundance of flowering shoots

Gentiana zollingeri is an annual photosynthetic plant that employs a mycoheterotrophic growth strategy during its underground seedling stage (initial mycoheterotrophy). Notably, the morphological characteristics of its flowering shoots, such as shoot size, leaf size, and leaf color, are highly variable, and it was hypothesized that these variations may be linked to nutritional mode. The morphological characteristics of G. zollingeri individuals were thus investigated alongside environmental factors, 13C abundance, and diversity of colonizing arbuscular mycorrhizal (AM) fungi. The majority of G. zollingeri flowering individuals were found to exhibit a high affinity for the specific AM fungi that exclusively colonize roots of the mycoheterotrophic seedlings, while other phylogenetically diverse AM fungi could also be detected. The leaves to shoot dry weight ratio (leaf ratio) was negatively correlated with the canopy openness in the habitat, suggesting that leaf development is impeded in sunny conditions. Furthermore, the shoot weight of G. zollingeri was positively correlated with leaf 13C abundance. Given that 13C enrichment can provide indirect evidence of mycoheterotrophy in AM plants, the results suggest that the utilization of carbon obtained through mycoheterotrophy, at least during the underground seedling stage, is crucial for G. zollingeri.

The molecular population structure of Swertia perennis (Gentianaceae) in Central Europe

Phylogeographic analysis of Swertia perennis, a typical European subalpine springtime species, revealed the existence of at least five major phylogenetic lineages. A large phylogeographic separation exists among these geographical regions, which confirms the existence of glacial refugia in the Pyrenees, but also in the Eastern and Central Alps. The results obtained from the analyzes indicate the existence of three major differences between the populations of the Alps and the Pyrenees, but also between the populations of the Alps and those of other geographical regions (Carpathians, southern Czech Republic, Sudetes and northern Poland). The studied populations from the Black Forest and from north-eastern and southern Poland are a relic of the former wider distribution of these (periglacial) genetic groups within Swertia perennis. Our results also confirm the existence of biogeographical links between the Carpathians and the Hercynian Range and the Alps. Certainly, there was an exchange of genes between populations located in the eastern Alps, the Carpathians and the Hercynian ranges (Czech Republic, Jeseníky, Sudetes, Ore Mountains). This confirms previous results of comparative studies on the genetic diversity of populations of other vascular plant species.

Phylogeography and ecological niche modeling implicate multiple microrefugia of Swertia tetraptera during quaternary glaciations

BACKGROUND

Climate fluctuations during the Pleistocene and mountain uplift are vital driving forces affecting geographic distribution. Here, we ask how an annual plant responded to the Pleistocene glacial cycles.

METHODS

In this study, we analyzed the population demographic history of the annual herb Swertia tetraptera Maxim (Gentianaceae) endemic to Qinghai-Tibetan Plateau (QTP). A total of 301 individuals from 35 populations of S. tetraptera were analyzed based on two maternally inherited chloroplast fragments (trnL-trnF and trnS-trnG). Phylogeographic analysis was combined with species distribution modeling to detect the genetic variations in S. tetraptera.

RESULTS

The genetic diversity of S. tetraptera was high, likely due to its wide natural range, high proportion of endemic haplotypes and evolutionary history. Fifty-four haplotypes were identified in S. tetraptera. Only a few haplotypes were widespread (Hap_4, Hap_1, Hap_3), which were dispersed throughout the present geographical range of S. tetraptera, while many haplotypes were confined to single populations. The cpDNA dataset showed that phylogeographic structuring was lacking across the distribution range of S. tetraptera. Analyses of molecular variance showed that most genetic variation was found within populations (70.51%). In addition, the relationships of the haplotypes were almost completely unresolved by phylogenetic reconstruction. Both mismatch distribution analysis and neutrality tests showed a recent expansion across the distribution range of S. tetraptera. The MaxEnt analysis showed that S. tetraptera had a narrow distribution range during the Last Glacial Maximum (LGM) and a wide distribution range during the current time, with predictions into the future showing the distribution range of S. tetraptera expanding.

CONCLUSION

Our study implies that the current geographic and genetic distribution of S. tetraptera is likely to have been shaped by Quaternary periods. Multiple microrefugia of S. tetraptera existed during Quaternary glaciations. Rapid intraspecific diversification and hybridization and/or introgression may have played a vital role in shaping the current distribution patterns of S. tetraptera. The distribution range of S. tetraptera appeared to have experienced contraction during the LGM; in the future, when the global climate becomes warmer with rising carbon dioxide levels, the distribution of S. tetraptera will expand.

Association of mycoheterotrophic Gentianaceae with specific Glomus lineages

Some plant species took an alternative evolutionary pathway in which they lost their photosynthetic capacity to depend exclusively on carbon supplied by arbuscular mycorrhizal fungi (AMF) in an association called mycoheterotrophy. Among them is Voyriella parviflora, a species of the family Gentianaceae, which is found in tropical regions such as the Amazon basin. Here, we assessed the identity of AMF symbionts associated with this species. DNA was isolated from eight Gentianaceae specimens and from litter and surrounding roots of photosynthetic plants. The atp1 gene was amplified by Sanger sequencing to determine the taxonomic affiliation of the mycoheterotrophic plants. A 280 bp region of the 18S rRNA gene of AMF was amplified with primers NS31/AML2 by high-throughput sequencing. The mycoheterotrophic specimens were assigned to V. parviflora with a bootstrap support of 72%. Glomus was the most abundant AMF genus, both in the mycoheterotrophic plants and in the litter and roots of photosynthetic plants. In addition, a few Glomus genotypes were abundantly enriched in the mycoheterotrophic plants, with only a few specimens colonized by Gigaspora, Acaulospora, and Scutellospora in a low proportion. These genotypes formed a cluster within a larger clade, suggesting that V. parviflora shows a preferential association with a narrow Glomus lineage which is not phylogenetically close to a previously identified V. parviflora's associated lineage. Furthermore, detecting fungi from other families suggests that V. parviflora is colonized by other genera, although with low frequency. These findings provide new insights into the association between AMF and mycoheterotrophic species and highlight the importance of considering trap culture-independent approaches in understanding this symbiosis.

Unraveling the secretion mechanism of the curious nectaries in Gentianaceae

Unusual nectaries were anatomically described as being usual traits for Gentianaceae. They are small, avascularized, and formed by 3 to 5 rosette cells with labyrinthine walls around one central cell. Such as nectaries have been reported for stems, petals, and sepals of different species of the family, however, there is no information on the mechanisms involved with the synthesis and release of secretion. Thus, this work aimed to unravel the mechanism of secretion and exudation of nectar for these curious nectaries using Calolisianthus speciosus as a model. Samples were processed according to standard methods for light and electron microscopy. Leaf and sepal nectaries were described, as were those of the apex of petals where ants were observed patrolling a darkened region. The enzymatic method was used for the detection of sugars, proteins, and amino acids in leaf and sepal exudates. The nectaries of petals of C. speciosus are similar to those of its leaves, sepals, and stem, although their activities are asynchronous. Polysaccharides were detected on the labyrinthine walls of rosette cells and protein in the opposite region of the cytoplasm. Labyrinthine walls increase the contact surface between rosette cells and the central cell, allowing for the transfer of secretion. After accumulation, the secretion is released to the subcuticular space of the central cell through disruption of the cuticle. The secretion and exudation of nectar were elucidated and involve distinct organelles.

Isolation and cytotoxic activities of undescribed iridoid and xanthone glycosides from Centaurium erythraea Rafn. (Gentianaceae)

Centaurium erythraea Rafn. (Gentianaceae) is used in internal traditional therapy as an anthelmintic, hypotensive, antipyretic, and antidiabetic. It is used externally for the treatment of wounds. Ursolic acid, maslinic acid, secologanin, secologanin dimethyl acetal, centauroside A, erythraeaxanthone I, erythraeaxanthone II, and demethyleustomin were isolated from aerial parts of Centaurium erythraea and were identified using spectroscopic methods, including NMR and mass spectrometry. The cytotoxic potency of undescribed compounds was evaluated by the XTT assay against human breast cancer MCF-7, MDA-MB-453 and mouse fibroblast 3T3-L1 cell lines. Erythraeaxanthone II was found to have the most potent cytotoxic activity.

Changes in female function and autonomous selfing across floral lifespan interact to drive variation in the cost of selfing

PREMISE

Morphological and developmental changes as flowers age can impact patterns of mating. At the same time, direct or indirect costs of floral longevity can alter their fitness outcomes. This influence has been less appreciated, particularly with respect to the timing of selfing. We investigated changes in stigma events, autonomous selfing, outcross seed set capacity, and autofertility-a measure representing the potential for reproductive assurance-across floral lifespan in the mixed-mating biennial Sabatia angularis.

METHODS

We examined stigma morphology and receptivity, autonomous self-pollen deposition, and seed number and size under autonomous self-pollination and hand outcross-pollination for flowers of different ages, from 1 d of female phase until 14 d. We compared autonomous seed production to maximal outcross seed production at each flower age to calculate an index of autofertility.

RESULTS

The stigmatic lobes begin to untwist 1 d post anthesis. They progressively open, sextend, coil, and increase in receptivity, peaking or saturating at 8-11 d, depending on the measure. Autonomous seed production can occur early, but on average remains low until 6 d, when it doubles. In contrast, outcross seed number and size start out high, then decline precipitously. Consequently, autofertility increases steeply across floral lifespan.

CONCLUSIONS

Changes in stigma morphology and receptivity, timing of autonomous self-pollen deposition, and floral senescence can interact to influence the relative benefit of autonomous selfing across floral lifespan. Our work highlights the interplay between evolution of floral longevity and the mating system, with implications for the maintenance of mixed mating in S. angularis.

A flower with several secretions: anatomy, secretion composition, and functional aspects of the floral secretory structures of Chelonanthus viridiflorus (Helieae-Gentianaceae)

Floral secretory structures have been reported for Gentianaceae; however, morphoanatomical studies of these glands are rare. We described the development and secretory activity of the colleters and nectaries throughout the floral development of Chelonanthus viridiflorus. We collected flower buds, flowers at anthesis, and fruits to be investigated using light and scanning electron microscopy. We performed histochemical tests on the secretion of colleters and used glycophyte to confirm the presence of glucose in nectar. Colleters are located on the ventral surface of sepals and nectaries occur in four regions: (i) the dorsal and (ii) ventral surfaces of sepals; (iii) apex of petals; and (iv) base of ovary. The colleters have a short peduncle and a secretory portion with homogeneous cells. They are active in flower buds and secrete polysaccharides and proteins. In flowers at anthesis, they begin to senescence presenting protoplast retraction, cell collapse, and lignification; these characteristics are intensified in fruit. The nectaries of sepals and petals have two to five cells surrounding a central cell through which the secretion is released. Nectaries are numerous, forming a nectariferous area on the dorsal surface of sepals, like that observed on petals, and can form isolated units on the ventral surface of sepals. They are active from flower buds to fruits. A region with secretory activity was identified at the base of the ovary. The secretion of colleters acts in the protection of developing organs, while nectaries are related to defenses against herbivores and the supply of nectar to potential robbers or pollinators.

The short but useful life of Prepusa montana Mart. (Gentianaceae Juss.) leaf colleters-anatomical, micromorphological, and ultrastructural aspects

Colleters are secretory structures involved in the protection of young and developing plant organs. Although the presence of colleters in Gentianales is described as a synapomorphy, studies on the morphofunctionality of colleters and the mechanisms underlying the synthesis and release of colleter secretion in Gentianaceae are scarce. Here, we described the ontogeny and the morphological and functional aspects of colleters of Prepusa montana, revealed the nature of the key compounds present in the secretion, and explored the cellular aspects of the synthesis and release of secretion and senescence of colleters. Samples of the stem apical meristem with leaf primordium and young leaves; adult and senescent leaves were observed using light and electron microscopy. The colleters, located in the axil of the leaf, have a protodermal origin and develop asynchronously. They are digitiform, possessing a short peduncle and a secretory head containing homogeneous cells with dense cytoplasm and abundant endoplasmic reticulum and Golgi bodies. The secretion, composed of polysaccharides and proteins, is accumulated in schizogenous spaces and released through the separation of peripheral secretory cells and loosening of the external periclinal wall. Presumably, senescence is caused by programmed cell death. The morphoanatomical characterization of P. montana leaf colleters described here is the first record for the genus and the peculiar accumulation of colleter secretion in schizogenous spaces expanding our knowledge on the diversity of these secretory structures. Our results also provide insights into programmed cell death as an eminent topic related to secretory structures.

Mycoheterotrophic seedling growth of Gentiana zollingeri, a photosynthetic Gentianaceae plant species, in symbioses with arbuscular mycorrhizal fungi

We found mycoheterotrophic seedling growth (initial mycoheterotrophy) of Gentiana zollingeri, a spring-flowering photosynthetic species of Gentianaceae family. Small seeds (about 300 µm in length) were buried in a habitat by using seed packets, and development of the subterranean seedlings to form shoots, more than 3 cm in length, was observed in symbiosis with arbuscular mycorrhizal (AM) fungi in the dark (i.e., underground of a field). Hyphal coils and their degenerations were observed in the root cortical cells of the subterranean seedlings as well as those of adult plants. Among the mycobionts identified on the basis of partial small subunit rDNA sequences, it was found that AM fungi of a lineage in Glomeraceae dominantly colonized, and the AM fungi were also dominant in adult individuals of G. zollingeri in three habitats separated one another by 17.2, 34.7, and 49.6 km. Though initial mycoheterotrophy in symbioses with AM fungi has been observed in some pteridophytes, this is the first study to demonstrate this type of symbiosis in a photosynthetic seed plant. The mycoheterotrophy means that an energy distribution occurs through the hyphal bridges of AM fungi among different photosynthetic seed plants, which may be important in constructing plant species diversity in some ecosystems.

Settling a family feud: a high-level phylogenomic framework for the Gentianales based on 353 nuclear genes and partial plastomes

PREMISE

Comprising five families that vastly differ in species richness-ranging from Gelsemiaceae with 13 species to the Rubiaceae with 13,775 species-members of the Gentianales are often among the most species-rich and abundant plants in tropical forests. Despite considerable phylogenetic work within particular families and genera, several alternative topologies for family-level relationships within Gentianales have been presented in previous studies.

METHODS

Here we present a phylogenomic analysis based on nuclear genes targeted by the Angiosperms353 probe set for approximately 150 species, representing all families and approximately 85% of the formally recognized tribes. We were able to retrieve partial plastomes from off-target reads for most taxa and infer phylogenetic trees for comparison with the nuclear-derived trees.

RESULTS

We recovered high support for over 80% of all nodes. The plastid and nuclear data are largely in agreement, except for some weakly to moderately supported relationships. We discuss the implications of our results for the order's classification, highlighting points of increased support for previously uncertain relationships. Rubiaceae is sister to a clade comprising (Gentianaceae + Gelsemiaceae) + (Apocynaceae + Loganiaceae).

CONCLUSIONS

The higher-level phylogenetic relationships within Gentianales are confidently resolved. In contrast to recent studies, our results support the division of Rubiaceae into two subfamilies: Cinchonoideae and Rubioideae. We do not formally recognize Coptosapelteae and Luculieae within any particular subfamily but treat them as incertae sedis. Our framework paves the way for further work on the phylogenetics, biogeography, morphological evolution, and macroecology of this important group of flowering plants.

Acetylcholinesterase inhibitor from Anthocleista vogelii leaf extracts

BACKGROUND

Anthocleista vogelii (Planch) is used in folk medicine in conditions related to inflammation and oxidative stress. This suggests that some of its constituents could possess ability to reduce oxidative damage to cells and ameliorate inflammatory conditions which are two prominent features in the brain of a person suffering from Alzheimer's disease.

AIM OF STUDY

The leaf extracts were investigated for their bioactive constituents in our quest for novel compounds for the management of Alzheimer's disease.

MATERIALS AND METHODS

Anthocleista vogelii crude leaf extract obtained from 80% methanol was successively partitioned with n-hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. This gave four solvent fractions of the crude extract. These fractions and isolated compound were subjected to acetylcholinesterase (AChE) inhibitory activity test using the microplate assay method. The structure of the isolated compound was determined using spectroscopic methods (1D and 2D NMR, and MS).

RESULTS

The results of the acetylcholinesterase inhibitory assay revealed that n-BuOH and ethyl acetate fractions had the best activity with IC₅₀ of 564.58 and 727.63 µg/mL respectively. Activity directed fractionation of each of these fractions led to the isolation of the same compound identified as a C-glucosylflavone; isovitexin-7-O-methyl ether (swertisin). This rare C-glucosylflavone co-exist as two rotamers and exhibited duplication of NMR signals. It is reported from this plant for the first time. Swertisin displayed better acetylcholinesterase inhibitory activity with IC₅₀ of 32.09 µg/mL than physostigmine (eserine) with IC₅₀ of 56.09 µg/mL used as a standard.

CONCLUSIONS

This study reports isolation and characterization of a rare C-glycosylflavone; isovitexin-7-O-methyl ether (swertisin). Isolated compound exhibited duplication of NMR signals and better acetylcholinesterase inhibitory activity than eserine used as a standard. The activity exhibited by this compound suggests that it could be useful in the management of Alzheimer's disease.

Antidiabetic activities of chloroform fraction of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Anthocleista vogelii Planch is a medicinal plant traditionally used in West Africa for the management and treatment of diabetes mellitus.

AIM OF THE STUDY

To determine the antidiabetic activities of chloroform fraction (CF) of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes.

MATERIALS AND METHODS

Inhibitory activities of CF against α-amylase and α-glucosidase activities were determined in vitro. Three weeks old rats were fed with high-fat diet for 9 weeks to induce obesity prior to further induction of diabetes using alloxan (150 mg/kg body weight, i.p.). Blood glucose levels and body weight were measured every 7 days throughout the experiment. Glucose tolerance was assessed in normal and CF-treated rats on day 21. Terminal blood samples were collected from sacrificed animals for the measurement of serum insulin levels. Pancreases were excised from treated and untreated animals for histopathological examination.

RESULTS

LCMS/MS chromatographic profile of CF via positive and negative modes revealed 13 and 23 compounds respectively. Further analysis revealed quebrachitol (QCT), loganin, sweroside, oleoside 11-methyl ester and ferulic acid, which have been previously reported for their antidiabetic activities, as constituents of CF. CF inhibited activities of α-amylase (IC₅₀ = 51.60 ± 0.92 µg/ml) and α-glucosidase (IC₅₀ = 5.86 ± 0.97 µg/ml) in a dose-dependent manner. Treatment of animals with obesity-diabetes with 100 and 200 mg/kg CF significantly improved glucose tolerance (P < 0.001) and enhanced serum insulin levels (P < 0.05) compared to diabetic control rats.

CONCLUSIONS

Antidiabetic activities of CF might be mediated via inhibition of α-amylase and α-glucosidase activities, elevation of serum insulin concentration, and enhancement of insulin and leptin sensitivity in obesity-diabetes rats. This study further substantiates the traditional use of A. vogelii in the management and treatment of diabetes in Africa and encourages further studies to investigate its mechanism of action.

[Study on Chemical Components of Tripterospermum chinense ( Ⅱ)]

OBJECTIVE

To investigate the chemical components of Tripterospermum chinense.

METHODS

Various column chromatography were used in the isolation and purification,and physiochemical constant determination and spectral analysis were adopted to determine the chemical structures.

RESULTS

A novel monoterpenoid and seven known compounds were isolated and identified as tripterospermum acid ester A( 1),strychnovoline( 2),p-hydroxybenzaldehyde( 3),isovitexin( 4),7-O-rhamnopyransoyl-isoorientin( 5),trifoliside( 6),2″-O-rhamnopyransoyl-trifoliside( 7) and sweroside( 8).

CONCLUSION

Compound 1 is a new monoterpenoid,compounds 2,3 are isolated from this plant for the first time.

Immunomodulatory potential of Enicostema axillare (Lam.) A. Raynal, a traditional medicinal plant

ETHNOPHARMACOLOGICAL RELEVANCE

Enicostema axillare (Lam.) A. Raynal., (Gentianaceae) has been used in traditional Indian system of medicine as depurative and for the treatment of psoriasis, intermittent fever and cancer. Ethnobotanical survey conducted in Theni District indicated a high consensus for this plant as blood purifier and to treat dermatopathy and venereal infections. The present study evaluated the immunomodulatory activity of the methanol extract of Enicostema axillare.

MATERIALS AND METHODS

In vivo immunomodulatory activity of Enicostema axillare methanol extract (100 and 200mg/kg b.w) was evaluated by assessing its effect on the total and differential leukocyte count, organ weight, hemaggultinating antibody titer, plaque forming cells, quantitative hemolysis of SRBC and delayed type hypersensitivity. Sheep red blood cells (SRBC, 5×10(8)cells/0.1mL) were used to immunize the animals. In vitro immunomodulatory potential of the extract was studied using peritoneal macrophages by evaluating its effects on NBT reduction, NO production and cytokine release.

RESULTS

The animals treated with Enicostema axillare methanol extract showed a significant (P≤0.05) increase in weight of the thymus and spleen. The total leukocyte and lymphocyte count was increased significantly (P<0.005) by the treatment. There was no significant alteration in neutrophil count. A dose dependent increase in antibody titer value was observed. A decreased response to DTH reaction induced by SRBC was recorded. A potential phagocytic response was seen on treatment with the extracts at 10 and 25μg/mL. The extract inhibited the release of pro-inflammatory cytokines and production of NO significantly in a dose dependent manner.

CONCLUSION

These findings suggested that the methanol extract of Enicostema axillare acted on both humoral and cell mediated immune functions and decreased the release of pro-inflammatory cytokines in the peritoneal macrophages.

Hypoglycemic activity of C-glycosyl flavonoid from Enicostemma hyssopifolium

CONTEXT

Enicostemma hyssopifolium Verdoon (Gentianaceae) has been documented for various therapeutic effects in traditional systems of medicine; the hypoglycemic and hypolipidemic activities are also well reported.

OBJECTIVE

Bioactivity guided fractionation of methanol extract of E. hyssopifolium to test the hypothesis that E. hyssopifolium and its constituents influence cells and systemic glucose homeostasis.

MATERIALS AND METHODS

Derived fraction and isolated compounds were studied for (1) aldose reductase (AR) inhibition, (2) α-glucosidase inhibition, (3) effect on gluconeogenesis in rat hepatoma, (4) cytoprotection against streptozotocin (STZ)-induced toxicity on RINm5F cells, (5) normalization of glycemic control in acute hyperglycemic rat model, and (6) insulin-releasing effect both in vitro and in vivo.

RESULTS

The results indicated that E. hyssopifolium can modify the glucose homeostasis at the cellular level. Two bioactive constituents were identified. Swertisin was found to inhibit AR (IC(50) 1.23 μg/mL) and α-glucosidase (IC(50) 1.89 μg/mL). It also possessed a significant cytoprotective action of RINm5F cell line against toxicant STZ. Swertiamarin was found to have hepatic gluconeogenesis inhibiting and insulin-releasing effect on rat hepatoma and RINm5F cells, respectively. The results of the in vivo study showed that swertiamarin, unlike the in vitro effect, produced no significant raise of insulin secretion. Swertisin normalized the serum glucose 60 min after high dose of glucose (2 g/kg, i.p.) in rats.

DISCUSSION AND CONCLUSION

These findings demonstrate that the fraction derived from the aerial part of E. hyssopifolium achieve normoglycemic status in hyperglycemic conditions via various mechanisms. The constituents swertiamarin and swertisin are responsible for bioactivity.

Hepatoprotective and antioxidant effects of the methanolic extract from Halenia elliptica

AIMS OF STUDY

Halenia elliptica, a medicinal herb of Tibetan origin, was commonly used in folk medicine to treat hepatitis. The aim of the present study is to evaluate the hepatoprotective and antioxidant activity of Halenia elliptica against experimentally induced liver injury.

MATERIALS AND METHODS

The antioxidant property of methanolic extract (ME) of Halenia elliptica was investigated by employing various established in vitro systems. The ME of Halenia elliptica was studied here for its hepatoprotective effects against CCl(4)-induced liver toxicity in rats. Activity was measured by monitoring the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total bilirubin.

RESULTS

The ME possessed strong antioxidant activity in vitro. The results of CCl(4)-induced liver toxicity experiment showed that rats treated with the ME of Halenia elliptica (100 mg/kg and 200 mg/kg), and also the standard treatment, silymarin (50 mg/kg), showed a significant decrease in ALT, AST, ALP, and total bilirubin levels, which were all elevated in the CCl(4) group (p<0.01). The results observed after administration of 100 mg/kg ME were comparable to those of silymarin at 50 mg/kg (p>0.05). The ME did not show any mortality at doses up to 2000 g/kg body weight.

CONCLUSION

These results seem to support the traditional use of Halenia elliptica in pathologies involving hepatotoxicity, and the possible mechanism of this activity may be due to strong free radical-scavenging and antioxidant activities of ME.

Effect of aqueous Enicostemma littorale Blume extract on key carbohydrate metabolic enzymes, lipid peroxides and antioxidants in alloxan-induced diabetic rats

The present study investigates the effect of oral administration of an aqueous Enicostemma littorale whole plant extract on some key carbohydrate metabolic enzymes and antioxidant defence in alloxan-induced diabetes in rats. Rats were rendered diabetic by alloxan (150 mg kg−1 body weight) administration. Oral administration of E. littorale extract for 45 days increased the activity of hexokinase and decreased the activities of glucose 6-phosphatase and fructose 1,6-bisphosphatase significantly in the serum, liver and kidney of diabetic rats. The extract lowered the concentration of thiobarbituric acid reactive substances and lipid hydroperoxides significantly in brain and increased it significantly in heart in diabetic rats. E. littorale administration increased the concentration of reduced glutathione and the activity of glutathione peroxidase in diabetic rats. The activities of superoxide dismutase and catalase were increased significantly by E. littorale treatment in diabetic rats. The effect of a 2 g kg−1 dose was greater than that of a 1 g kg−1 dose. Insulin (6 units kg−1) normalized all the parameters in diabetic rats. Our study has provided evidence for the antidiabetic activity of E. littorale aqueous extract. This study can also be extrapolated to clinical studies in future.

Evaluation of effect of aqueous extract of Enicostemma littorale Blume in streptozotocin-induced type 1 diabetic rats

The present investigation was undertaken to standardize and study the dose-dependent effect of three weeks treatment with hot and cold aqueous extract of E. littorale (0.5, 1 and 2 g/kg, po) on streptozotocin (STZ) induced type I diabetic (confirmed by histopathology) rats (45 mg/kg, iv single dose). Treatment of rats with STZ produced cardinal signs of diabetes-mellitus like a significant loss of body weight, polyuria and polydipsia. There was also a significant increase in fasting blood glucose levels and AUC(glucose) associated with decrease in insulin levels and AUC(insulin) in STZ-diabetic rats. Treatment with E. littorale hot extract (1 and 2 g/kg) significantly reduced the elevated food intake and water intake, glucose and AUC(glucose) levels of diabetic rats. There was also a significant increase in serum cholesterol, serum triglyceride in the STZ diabetic rats. Treatment with E. littorale hot extract (1 and 2 g/kg) significantly decreased all these elevated levels in diabetic rats. Hot aqueous extract of E. littorale at 0.5 g/kg produced a significant decrease in serum glucose and triglycerides. At this doses serum cholesterol and AUC(glucose) were not found to be altered significantly.TLC finger-print profiles were established for the aqueous extract using HPTLC. Swertiamarin, which was used as a chemical marker, was found to be one of the major components in the hot extract while it was absent in cold extract. The results suggest that E. littorale possesses potential antidiabetic activity and improves lipid profile at a small dose of 0.5 g/kg.

Anthocleistenolide, a new rearranged nor-secoiridoid derivative from the stem back of Anthocleista vogelii

A new rearranged nor-secoiridoid, anthocleistenolide ( 1), along with the known 1-hydroxy-3,7-dimethoxyxanthone ( 2), 1-hydroxy-3,7,8-trimethoxyxanthone ( 3), 7 alpha-hydroxysitosterol ( 4) and sitosterol 3- O-beta- D-glucopyranoside ( 5), were isolated from the stem back of Anthocleista vogelii. Their structures were elucidated on the basis of spectral studies and comparison with published data. Compounds 1 - 3 and 5 were evaluated for their antibacterial and antifungal activities. Relatively low anti-staphylococcal (MIC = 200 microg/mL against Staphylococcus aureus) and anti-enterococcal (MIC = 100 microg/mL against Enterococcus faecalis) activities were observed for 1, while compounds 2 and 3 were active against Candida parapsilosis (MIC = 200 microg/mL for 2 and 25 microg/mL for 3). Compound 5 was inactive against all the bacterial and fungal species used.

[Pathogen identification of leaf-spot and its biological characteristics on Gentiana spp]

OBJECTIVE

To clear the pathogen of leaf-spot on (Gentiana spp. in Gansu province, and to control the disease theoretically.

METHODS

The symptoms were obsersed and described in the field. The pathogen was identified on the base of morphology. The factors influencing the colony growth, myceliuim gross and sporulation were studied by the suspension and solid meedia.

RESULTS

The pathogen was identified as Septoria gentionae. PDA and PSA were benefitial for colony growth and sporolation. The optimum temperature for colony growth, sporulation and mycelium gross were 25 degrees C. 20 degrees C and 20 degrees C respectively. The optimum pH was 7 for the pathogen growing and sporulation. 12h light plus l2 h dark, 8 hours UV plus 16 h light were beneficial to colony growing and sporulation. All-dark, 8 hours UV plus 16 hours dark were good for mycelium gross. Among 11 carbon sources, xylose, sucrose and soluble starch were very good for colony growth. Sucrose was best for sporulation, while raffilose best for mycelium gross. Among nitrogen sources, colony growth and sporulation quality reached highest on alanine, urea and NANO2 were not utilized very well. NH4H2PO4 was the best for sporulation and mycelium gross.

Hypolipidaemic and antioxidant effect of Enicostemma littorale Blume aqueous extract in cholesterol fed rats

Enicostemma littorale aqueous extract (1.5 g/100 g body weight/day, p.o.) was administered to rats along with hypercholesterolaemic diet for 6 weeks and the hypolipidaemic and antioxidant effect was evaluated. Feeding cholesterol increased serum cholesterol, serum triglycerides, LDL, VLDL and decreased HDL levels as compared to normal diet fed rats. Enicostemma littorale treatment increased HDL levels and decreased serum cholesterol, triglyceride, LDL, VLDL, LDL/HDL ratio. In addition, treatment with the extract showed a decrease in activities of erythrocyte catalase, superoxide dismutase and lipid peroxidation levels, with an increase in reduced glutathione levels as compared to cholesterol fed untreated rats. Liver and kidney cholesterol levels and triglyceride levels were also decreased in Enicostemma littorale treated rats. Hepatic HMG CoA reductase activity was significantly reduced in the extract treated hypercholesterolemic rats. Lovastatin was used as a reference drug. The hypolipidaemic and antioxidant effect of Enicostemma littorale aqueous extract in cholesterol fed rats is being reported for the first time.

Phenolic glycosides from Potalia amara

Investigation of the stem bark of the unique Amazonian herbal plant Potalia amara yielded two new phenolic glycosides, potalioside A (1) and B (2), along with di-O-methylcrenatin (3), 2,6-dimethoxy-4-hydroxyphenol 1-glucoside and sweroside. The structures of potalioside A and B were established by interpretation of spectral data as 4-hydroxymethyl-2,6-dimethoxyphenyl 1-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside and 4-hydroxymethyl-2,6-dimethoxyphenyl 1-O-beta- D-xylopyranosyl(1-->6)- beta-D-glucopyranoside, respectively.

Inhibitory effects of the Gentiana macrophylla (Gentianaceae) extract on rheumatoid arthritis of rats

Acute treatment of rheumatoid rats with an extract from the roots of Gentiana macrophylla (Gentianaceae) produced a significant inhibitory effect on rheumatoid arthritis (RA). When rats were administered the Gentiana macrophylla extract orally at a daily dose of 100 mg/kg body weight, the prostaglandin E(2) (PGE(2)) levels in the inflammatory tissues, sole thickness, and ankle circumferences of feet were significantly decreased. The anti-inflammatory activity observed in Gentiana macrophylla is comparable to that observed in prednisone. These observations suggest that Gentiana macrophylla displays considerable potency in anti-inflammatory action and could be used as an anti-inflammatory agent in the control of inflammation of rheumatoid arthritis.

Efficacy of Enicostemma littorale in Type 2 diabetic patients

Pills prepared from Enicostemma littorale (Gentianaceae) were administered to 84 patients with Type 2 Diabetes for three months. Estimation of various biochemical parameters showed that E. littorale reduced blood glucose as well as serum insulin levels and prevented the progression of complications in diabetic patients. Significant improvement in kidney function, lipid profile and blood pressure was observed suggesting that E. littorale is an effective herbal antidiabetic.

Evaluation of extracts of Anthocleista djalonensis, Nauclea latifolia and Uvaria afzalii for activity against bacterial isolates from cases of non-gonococcal urethritis

Whole root preparations of three Nigerian medicinal plants, Anthocleista djalonensis, Nauclea latifolia and Uvaria afzalii, used traditionally in combination treatment of sexually transmitted diseases (STD), were extracted by maceration in ethanol, cold and hot water, respectively. The extracts were tested, by agar diffusion and macrobroth dilution methods, for activity against five strains of Staphylococcus aureus and two of Escherichia coli isolated from cases of STD and or urethritis. Four typed bacterial strains, S aureus ATCC 12600, Bacillus subtilis ATCC 6051, Pseudomonas aeruginosa ATCC 10145 and Escherichia coli ATCC 117755 were included as reference organisms. Ethanolic and cold-water extracts of Anthocliesta djalonensis exhibited activity against 9 and 7, respectively, of the 11 test organisms. They were bacteriostatic at minimum inhibitory concentrations (MIC) to the Gram positive strains but bactericidal to the Gram negative strains. Similar crude extracts of Uvaria afzalii showed bactericidal activity restricted to Gram positive (Staphylococcus aureus and Bacillus subtilis) strains. Nauclea latifolia extracts were bacteriostatic to both Gram positive and Gram negative strains. No test strain was susceptible to the hot water extracts of Nauclea latifolia but five and seven strains, were respectively susceptible to similar extracts of Anthocliesta djalonensis and Uvaria afzalii. Of the seven column chromatographic fractions of the ethanolic extract of Uvaria afzalii, F(ua-1) exhibited a bactericidal activity restricted to the Gram negative Escherichia coli strains, which were not susceptible to the crude extract. Fractions, F(ua-2), F(ua-3) and F(ua-4), like the crude extract, were bactericidal against the Gram positive strains only. Thus, partial purification seems to broaden the spectrum of activity and generally improve the potency of Uvaria afzalii. These results apparently justify the use of the three plants in treatment of STD.

[Comparative choleretic properties of natural xanthone compounds from Gentianopsis barbata]

Comparative data are presented for the choleretic activity of xanthones isolated from Gentianopsis barbata (Froel.) Ma. (Gentianaceae family): a sum of xanthone glycosides (I) and aglycons (II); xanthone aglycons, including decussatin [1-(OH)-3,7,8-(OCH3)3] (III) and gentiacaulein [1,7-(OH)-3,8-(OCH3)2] (IV); and xanthone glycoside gentiabavaroside [1-O-primverosyl-7-(OH)-3,8-(OCH3)2] (V). It was established that (II) is superior to (I) with respect to cholagogic effect and is inferior to (III) and (IV) with respect to cholatostimulant action.

Effect of chronic treatment with Enicostemma littorale in non-insulin-dependent diabetic (NIDDM) rats

We have studied the effect of aqueous extract of Enicostemma. littorale (2 g/kg p.o.) daily for 6 weeks in neonatal non-insulin-dependent diabetes mellitus (NIDDM) rats. To induce NIDDM a single dose injection of STZ (70 mg/kg; i.p.) was given to the 5-day-old pups. After 3 months of STZ injection when animals were confirmed as diabetic, E. littorale was administered for 6 weeks. Fasting and fed glucose and insulin levels in NIDDM were significantly (P<0.05) higher than control rats and they were significantly decreased by the treatment with E. littorale. Results of the oral glucose tolerance test (OGTT) showed a significant (P<0.05) decrease in both AUC(glucose) and AUC(insulin) values in NIDDM treated group. Insulin sensitivity (K(ITT)) index of NIDDM control was significantly lower as compared with Wistar control and this was significantly (P<0.05) increased after treatment with E. littorale. Treatment with E. littorale also decreased the elevated cholesterol, triglyceride and creatinine levels observed in NIDDM rats. Our data suggest that aqueous extract of E. littorale is a potent herbal antidiabetic. It produces an increase in insulin sensitivity, normalizes dyslipidaemia and provides nephroprotection in diabetic rats.

Antimicrobial and phytochemical studies of Swertia corymbosa

The aqueous, methanol, chloroform and hexane extracts of Swertia corymbosa were tested (in vitro) for their antimicrobial efficiency. Maximum inhibitory activity was noticed against Staphylococcus aureus and Salmonella typhi.

Vasodilator activity of crude methanolic extract of Gentiana kokiana Perr. et Song. (Gentianaceae)

Gentiana kokiana Perr. et Song. is a plant employed in the traditional medicine of Tuscany (Italy) as antihypertensive remedy. The aim of this work was to evaluate a possible vascular action of the plant and to investigate its mechanism of action. The methanolic extract of roots showed an endothelium-independent vasodilator activity in aortic rings pre-contracted by norepinephrine (NE) 3 microM and a marked depression of the contracturant responses induced by KCl and caffeine, and by NE, both in Tyrode solution and Ca2+-free Tyrode solution. An action on the Ca2+-extracellular influx was discarded, while release or uptake mechanisms of the sarcoplasmic reticulum were hypothesized. However, the incapacity of cyclopiazonic acid (20 microM), a blocker of Ca2+/ATPase of the sarcoplasmic reticulum, to reduce the vasodilator action of the extract allowed to exclude the involvement of such a mechanism. A possible involvement of the ryanodine-sensitive Ca2+ channels is suggested.

alpha-Glucosidase inhibitory activity of Mangifera indica bark

The ethanolic extracts of Lawsonia inermis leaves, Holarrhena antidysenterica bark, Swertia chirata whole plant and Mangifera indica bark were tested (in-vitro) for alpha-glucosidase inhibitory activity. M. indica extract was found to be the most potent, with an IC(50) value of 314 microg/ml.

A xanthone from Shultesia guianensis

The isolation of 1-hydroxy-3,7-dimethoxyxanthone (1) from Shultesia guianensis is reported along with relevant NMR spectra, including new data by two-dimensional NMR experiments (HMQC and HMBC).